- Serum creatinine ≤ 1.5 mg/dL or calculated creatinine clearance ≥ 60 mL/min (Calculated by Cockroft and Gault method. Creatinine clearance (mL/min) = (140-age) x weight (kg)/72 x (serum creatinine in mg/dL) = ml**/min (**for females, multiply results by 0.85))